Variable gap hard stop design

ABSTRACT

A reaction system for processing semiconductor substrates is disclosed. The reaction system includes a susceptor for holding the substrate as well as a baseplate as a part of housing for the reaction system. A pin located on the susceptor can interact with a baseplate feature located on the baseplate to result in a variable gap between the susceptor and the baseplate. The baseplate feature may take the form of a series of steps, a wedge, or a milled-out feature.

FIELD OF INVENTION

The present disclosure generally relates to semiconductor processingtools. More particularly, the disclosure relates to a wafer handlingmechanism comprising a susceptor and a baseplate of a reaction region.

BACKGROUND OF THE DISCLOSURE

Semiconductor processing typically involves fabrication of devices, suchas transistors, diodes, and integrated circuits, upon a thin piece ofsemiconductor material called a substrate. The semiconductor processingtakes place in a reaction region, where gases are passed over thesubstrate, resulting in a controlled deposit of material upon thesubstrate. The substrate is lifted into the reaction region by asusceptor.

FIG. 1 illustrates such a prior art reaction system 100. The reactionsystem 100 includes a reaction region 105 and a substrate loading region110. The reaction region 105 is defined by a reaction region housing 115and a reactant distribution system 120. The reactant distribution system120 is illustrated as a showerhead gas flow system, but could be across-flow designed system. Separating the reaction region 105 and thesubstrate loading region 110 is a baseplate 125. A substrate chamberhousing 130 defines the substrate loading region 110.

In FIG. 1, the reaction system 100 is in a substrate loading mode, as asubstrate 135 is loaded on top of a susceptor 140. The susceptor 140 ismoved up and down by a movement element 145. The movement element 145may also allow rotation of the susceptor 140 and the substrate 135.Also, a substrate loading mechanism 150 is configured to load and unloadthe substrate 135 onto the susceptor 140.

Disposed at various points along the susceptor 140 are a set of pads155. The pads 155 are disposed between the susceptor 140 and thebaseplate 125. The pads prevent direct physical contact between thesusceptor 140 and the baseplate 125.

FIG. 2 illustrates the reaction system 100 in a substrate processingmode. The substrate 135 is moved into the reaction region 105 by thesusceptor 140 and the movement element 145. When the reaction system 100is in the substrate processing mode, the pad 155 in the susceptor 140will contact the baseplate 125.

FIG. 3 shows a zoomed view of the contact between the pad 155 and thebaseplate 125. A gap 160 is formed between the susceptor 140 and thebaseplate 125 during processing of substrate 135. The purpose of the gap160 is to allow fluid communication between the inside of the reactionregion and outside the susceptor. A height 165 of the pads 155 can rangebetween 0.001 inches (approximately 25 μm) and about 0.05 inches(approximately 1275 μm). When the pad 155 contacts the baseplate 125,the gap 160 will be the height of the pad 155 that is above a susceptorsurface 140A.

Over time, continued processing in the reaction region 105 can result ina deposition of reactive materials on and around the pads 155 of thesusceptor 140. This deposition build-up can lead to the reduction insize of the gap 160. As a result, the build-up may change the flowdynamics inside and outside the reaction region 105. This can causeissues of contamination and defects in the processed substrate 135.

In addition, continued contact between the pads 155 and the baseplate125 may result in an erosion of the pads 155. As shown in FIG. 3A, aresult of the continued contact is a reduction in a height 165′ of thepads 155 as well as a reduction in a gap 160′. The flow dynamics insideand outside the reaction region 105 will be affected.

One course of action exists to deal with the deposition build-up. Thereaction region may be opened and the pads may be replaced. In addition,the reaction region itself may be replaced. However, with these steps,the reaction region may be disassembled. The disassembly would takeplace after a particular number of cycles or substrates processed. Thisnumber was determined through the use of historical data that monitoredhow the deposition build-up of materials occurred. The disassembly isgenerally not feasible as it leads to processing downtime.

As a result, it is desired to have an arrangement for the reactionregion to address the issue of a shrinking gap due to build-up withoutthe disassembly of the reaction region.

SUMMARY OF THE DISCLOSURE

According to at least one embodiment of the invention, a reaction systemis disclosed. The reaction system includes a susceptor, a pin located onthe susceptor, a baseplate for interacting with the susceptor, amovement element for moving the susceptor, and a baseplate feature onthe baseplate. Interaction between the susceptor and the baseplateresults in a variable gap between the susceptor and the baseplate. Thevariable gap is adjustable based on the location of the pin's contact ofthe baseplate feature. The baseplate feature may take at least one ofthe following forms: a series of steps, a wedge, or a milled-outfeature.

According to at least one embodiment of the invention, a baseplateassembly is disclosed. The baseplate assembly includes a baseplate and abaseplate feature located on the baseplate. The baseplate and thebaseplate feature are configured to interact with a pin located on asusceptor that holds a substrate, such that a location of contactbetween the pin and the baseplate feature or the baseplate will resultin a variable gap between the baseplate and the susceptor. The baseplatefeature may take at least one of the following forms: a series of steps,a wedge, or a milled-out feature.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the attachedfigures, the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

These and other features, aspects, and advantages of the inventiondisclosed herein are described below with reference to the drawings ofcertain embodiments, which are intended to illustrate and not to limitthe invention.

FIG. 1 is a cross-sectional view of a prior art reaction system in asubstrate loading mode.

FIG. 2 is a cross-sectional view of a prior art reaction system in asubstrate processing mode.

FIG. 3 is a zoomed view of a prior art reaction system including a pad,a susceptor, and a baseplate as shown in FIG. 2.

FIG. 3A is a zoomed view of a prior art reaction system including a pad,a susceptor, and a baseplate.

FIG. 4 is a cross-sectional view of a reaction system in a substrateloading mode according to one embodiment of the invention.

FIG. 5 is a top elevation view of a susceptor according to oneembodiment of the invention.

FIG. 6 is an elevation view of a baseplate according to one embodimentof the invention.

FIG. 7 is an elevation view of a susceptor and a baseplate according toone embodiment of the invention.

FIG. 8 is a cross-sectional view of a reactor system in a substrateprocessing mode according to one embodiment of the invention.

FIG. 9 is a zoomed view of a reaction system including a pad, asusceptor, and a baseplate according to one embodiment of the inventionas shown in FIG. 8.

FIGS. 10A-10D are zoomed cross-sectional views of a reaction systemincluding a pad, a susceptor, and a baseplate according to oneembodiment of the invention as shown in FIG. 8.

FIG. 11 is a cross-sectional view of a reaction system in a substrateloading mode according to one embodiment of the invention.

FIG. 12 is an elevation view of a baseplate according to one embodimentof the invention.

FIG. 13 is a zoomed view of a reaction system including a pad, asusceptor, and a baseplate according to one embodiment of the inventionas shown in FIG. 11.

FIGS. 14A-14B are side perspective views of a reaction system includinga pad, a susceptor, and a baseplate according to one embodiment of theinvention as shown in FIG. 11.

FIG. 15 is a zoomed view of a reaction system according to oneembodiment of the invention.

FIGS. 16A-16B are side perspective views of a reaction system as shownin FIG. 15.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help improve understanding ofillustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below.

FIG. 4 illustrates a reaction system 200 according to at least oneembodiment of the invention. The reaction system 200 includes a reactionregion 205 and a substrate loading region 210. The reaction region 205is defined in part by a reaction region housing 215, a reactantdistribution system 220, and a baseplate 225. The substrate loadingregion 210 is defined in part by a substrate loading housing 230. Thereactant distribution system 220 is responsible for passing a gaseousreactant over a substrate to allow for deposition of the reactantmaterial. As illustrated, the reactant distribution system 220 is ashowerhead system. However, one of ordinary skill in the art wouldunderstand that a cross-flow system may be substituted for theshowerhead system for the reactant distribution system 220.

The reaction system 200 also includes a susceptor 235 for holding asubstrate 240. The susceptor 235 has a lower surface 235A. A movementelement 245 moves both the susceptor 235 and the substrate 240 into thereaction region 205. Also, the movement element 245 is configured torotate the susceptor 235 and the substrate 240. Furthermore, a substrateloading mechanism 250 is disposed within the susceptor in order to loadand unload the substrate 240 from the susceptor 235.

Located on a lower surface 225A of the baseplate 225 are a set ofbaseplate features 255. According to this embodiment of the invention,the baseplate feature 255 is illustrated as having a series of steps.The steps can range between 0.001 and 0.05 inches in height. Morepreferably, the steps can range between 0.004 and 0.012 inches inheight. The baseplate feature 255 will be in contact with a pin 260embedded within the susceptor 235.

FIG. 5 illustrates the susceptor 235 and the substrate 240 according toat least one embodiment of the invention. The susceptor 235 isconfigured to hold the substrate 240. In addition, the pin 260 isinstalled into the lower surface 235A of the susceptor 235. While it isillustrated that there are three pins installed in the susceptor 235,one of ordinary skill in the art would recognize that any number of pinsmay be used. An exemplary pin is disclosed in U.S. Pat. No. 8,216,380 toWhite et al, entitled GAP MAINTENANCE FOR OPENING TO PROCESS CHAMBER,the contents of which are hereby incorporated by reference to the extentsuch content does not conflict with the present disclosure. The pin 260may have a height between 0.001 inches (approximately 25 μm) and about0.05 inches (approximately 1275 μm). The pin 260 may also compriseCelazole® (PolyBenzImidazole) pads, although other materials are alsopossible.

FIG. 6 illustrates a side of the baseplate 225 that is in contact withthe pin 260 located on the susceptor 235 according to at least oneembodiment of the invention. Disposed on the lower surface 225A of thebaseplate 225 are the plurality of baseplate features 255. The baseplatefeatures 255 are illustrated as having a first step 255A, a second step225B, and a third step 255C. One of ordinary skill in the art wouldrecognize that the number and the orientation of baseplate features 255can be modified and arranged depending upon the number of pins 260.

FIG. 7 illustrates the overlay between the baseplate 225 and thesusceptor 235 (shown as dotted lines) when the reaction system 200 is ina substrate processing mode according to at least one embodiment of theinvention. The overlay is such that the pins 260 located on thesusceptor 235 are in contact with one of the first step 255A, the secondstep 255B, or the third step 255C of the baseplate features 255 or thelower surface 225A of the baseplate 225. It is envisioned that thecontact between the pins 260 and the baseplate features 255 take placeat the same step level of the baseplate feature 255. This would allowfor a consistent size of the gap between the susceptor 235 and thebaseplate 225. The susceptor 235 is configured to rotate along adirection A around an axis X such that the pins 260 can contact thebaseplate 225 at different locations on the baseplate features 255. Theprocess of adjusting the size of the gap between the susceptor 235 andthe baseplate 225 by adjusting the position of the pins is known asindexing.

The reaction system 200 is shown in a substrate processing mode in FIG.8 according to at least one embodiment of the invention. In this mode,the movement element 245 has elevated the susceptor 235 and substrate240 into the reaction region 205. As a result, the pin 260 on thesusceptor 235 is in contact with the baseplate 225.

The contact of the pin 260 onto the baseplate 225 is shown in greaterdetail in FIG. 9. The baseplate feature 255 is shown extending from abottom surface of the baseplate 225. The baseplate feature 255 has aplurality of surfaces that contact the pin 260. These surfaces are shownin detail in FIGS. 10A-10D.

In FIG. 10A, the pin 260 contacts a lower surface 225A on the baseplate225. The contact between the pin 260 and the baseplate feature surface255A forms a gap 270A. At this height of the gap 270A, the reactionsystem 200 may process a predetermined number of substrates 240. Forexample, the reaction system 200 may process five thousand substrateswith the pin 260 in contact with the lower surface 225A. During thistime, materials from the deposition reaction may enter and buildupwithin the gap 270A, reducing its size and potentially leading tocontamination and defects in the substrate 240. As a result, thereaction system 200 may adjust for the shrinking gap.

In an indexing process, the movement element 245 is capable of loweringthe susceptor 235 in a direction C and shifting it to the right in adirection B as shown in FIG. 10B. The movement element 245 may then putthe pin 260 in contact with a first step 255A of the baseplate feature255. The result of this contact is the formation of a gap 270B. The gap270B would be greater in size than the gap 270A.

At this height of the gap 270B, the reaction system 200 may process apredetermined number of substrates 240. For example, the reaction system200 may process five thousand substrates with the pin 260 in contactwith the first step 255A. During this time, materials from thedeposition reaction again may enter into the gap 270B, reducing its sizeand potentially leading to contamination and defects in the substrate240.

As shown in FIG. 10C, the indexing process continues and the movementelement 245 is capable of lowering the susceptor 235 in a direction C,shifting it to the right in a direction B, and then putting the pin 260in contact with a second step 255B. The result of this contact is theformation of a gap 270C. The gap 270C would be greater in size than thegap 270B or the gap 270A.

At this height of the gap 270C, the reaction system 200 may process apredetermined number of substrates 240. For example, the reaction system200 may process five thousand substrates with the pin 260 in contactwith the second step face 255B. During this time, materials from thedeposition reaction again may enter into the gap 270C, reducing its sizeand potentially leading to contamination and defects in the substrate240.

As shown in FIG. 10D, in another step of the indexing process, themovement element 245 is capable of lowering the susceptor 235 in adirection C, shifting it to the right in a direction B, and then puttingthe pin 260 in contact with a third step 255C. The result of thiscontact is the formation of a gap 270D. The gap 270D would be greater insize than the gap 270C, the gap 270B, or the gap 270A.

At this height of the gap 270D, the reaction system 200 may process apredetermined number of substrates 240. For example, the reaction system200 may process five thousand substrates with the pin 260 in contactwith the baseplate feature surface 255D. During this time, materialsfrom the deposition reaction again may enter into the gap 270D, reducingits size and potentially leading to contamination and defects in thesubstrate 240.

FIG. 11 illustrates a reaction system 300 according to at least oneembodiment of the invention. The reaction system 300 includes a reactionregion 305 and a substrate loading region 310. The reaction region 305is defined in part by a reaction region housing 315, a reactantdistribution system 320, and a baseplate 325. The substrate loadingregion 310 is defined in part by a substrate loading housing 330. Thereactant distribution system 320 is responsible for passing a gaseousreactant over a substrate to allow for deposition of the reactantmaterial. As illustrated, the reactant distribution system 320 is ashowerhead system. However, one of ordinary skill in the art wouldunderstand that a cross-flow system may be substituted for theshowerhead system for the reactant distribution system 320.

The reaction system 300 also includes a susceptor 335 for holding asubstrate 340. The susceptor 335 has a lower surface 335A. A movementelement 345 moves both the susceptor 335 and the substrate 340 into thereaction region 305. Also, the movement element 345 is configured torotate the susceptor 335 and the substrate 340. Furthermore, a substrateloading mechanism 350 is disposed within the susceptor in order to loadand unload the substrate 340 from the susceptor 335.

Located on a lower surface 325A of the baseplate 325 are a set ofbaseplate features 355. The baseplate feature 355 is illustrated as aseries of wedges. The wedges can range between 0.001 and 0.05 inches inheight. Furthermore, it may be preferred that the wedges be between0.004 and 0.012 inches in height. The baseplate feature 355 will be incontact with a pin 360 embedded within the lower surface 335A of thesusceptor 335.

FIG. 12 illustrates a side of the baseplate 325 that is in contact withthe pin 360 located on the susceptor 335 according to at least oneembodiment of the invention. Disposed on the lower surface 325A of thebaseplate 325 are the plurality of baseplate features 355. The baseplatefeatures 355 are arranged to allow for a consistent gap between thebaseplate 325 and the susceptor 335. One of ordinary skill in the artwould recognize that the number of baseplate features 355 can bemodified and arranged depending upon the number of pins 360.

The reaction system 300 is shown in a substrate processing mode in FIG.13 according to at least one embodiment of the invention. In this mode,the movement element 345 has elevated the susceptor 335, such that thepin 360 on the susceptor 335 is in contact with the lower surface 325Aof the baseplate 325. The baseplate feature 355 has a front edge 355Aand a back edge 355B.

In FIG. 14A, an indexing process according to at least one embodiment ofthe invention is illustrated. The pin 360 contacts a baseplate surface325A on the baseplate 325. The contact between the pin 360 and thebaseplate surface 325A forms a gap 370A. At this height of the gap 370A,the reaction system 300 may process a predetermined number of substrates340. For example, the reaction system 300 may process five thousandsubstrates with the pin 360 in contact with the baseplate surface 325A.During this time, materials from the deposition reaction may enter andbuildup within the gap 370A, reducing its size and potentially leadingto contamination and defects in the substrate 340. As a result, thereaction system 300 may have to adjust for the shrinking gap.

The movement element 345 is capable of lowering the susceptor 335 in adirection C and shifting it to the right in a direction B. The movementelement 345 may then put the pin 360 in contact with a front edge 355Aof the baseplate feature 355 as shown in FIG. 14B.

The result of this contact is the formation of a gap 370B. The gap 370Bwould be greater in size than the gap 370A.

At this height of the gap 370B, the reaction system 300 may process apredetermined number of substrates 340. For example, the reaction system300 may process five thousand substrates with the pin 360 in contactwith the front edge 355A. During this time, materials from thedeposition reaction again may enter into the gap 370B, reducing its sizeand potentially leading to contamination and defects in the substrate340. At least one embodiment of this invention is able to allow the pin360 to be lowered and shifted such that the pin 360 would be in contactwith the back edge 355B of the baseplate feature 355. This arrangementwould potentially avoid the need for an unnecessary shutdown of thereaction system.

FIG. 15 illustrates a reaction system according to at least oneembodiment of the invention. The reaction system includes a reactionregion 405 and a substrate loading region 410. The reaction region 405is defined by a reaction region housing 415 and a baseplate 425. Thesubstrate loading region is defined by a substrate region housing 430.

A susceptor 435 holds a substrate 440 and raises it into the reactionregion 405. The susceptor 435 is moved by a movement element 445. Withina lower surface 435A of the susceptor 435, a pin 460 is installed. Thepin 460 interacts with the baseplate 425, which has a lower surface425A. Within the lower surface 425A, a series of baseplate features 455is milled or carved out of the baseplate 425. The baseplate features 455have a top surface 455B and a sloped surface 455C.

FIG. 16A illustrates the interaction between the pin 460 and thebaseplate features 455 according to an indexing process in accordancewith at least one embodiment of the invention. The pin 460 is touchingthe top surface 455B of the baseplate feature 455, which also has avertical surface 455A. The vertical surface 455A can range between 0.001and 0.05 inches in height. Furthermore, it may be preferred that thevertical surface 455A be between 0.004 and 0.012 inches in height.

When the pin 460 touches the top surface 455B, the lower surface 425A ofthe baseplate 425 is touching or almost touching the lower surface 435Aof the susceptor 435. This results in a little or no gap 470A betweenthe baseplate 425 and the susceptor 435. A benefit that results fromthis very small gap 470A is a way to determine the alignment between thebaseplate 425 and the susceptor 435. In addition, the small gap 470Awould also serve as determining whether either the baseplate 425 or thesusceptor 435 or both are flat without suffering from any warpingeffects.

The arrangement shown in FIG. 16A would result in a very low leakagerate of gaseous pressure from the reaction region 405 into the substrateloading region 410. As a result, should there be a high leakage ratewhen the pin 460 is touching the top surface 455B, this will serve as analert to an operator of the reaction system of a potential system errorin the parts of the system.

After processing a number of substrates with the reaction system in thearrangement shown in FIG. 16A, the susceptor 435 may be moved such thatthe pin 460 touches another portion of the baseplate feature 455. Thismovement is shown in FIG. 16B, as the susceptor 435, through theassistance of the movement element 445, moves in a direction B. Themovement causes the pin 460 to be incident on the sloped surface 455C ofthe baseplate feature 455. As a result, a gap 470B increases in sizebetween the baseplate 425 and the susceptor 435. The leakage rate due togaseous pressure from the reaction region 405 into the substrate loadingregion 410 should be greater due to the increased gap size. Additionalsubstrates may be processed in this position, with additional movementalong the direction B potentially resulting in the pin 460 beingincident on the lower surface 425A of the baseplate 425.

The particular implementations shown and described are illustrative ofthe invention and its best mode and are not intended to otherwise limitthe scope of the aspects and implementations in any way. Indeed, for thesake of brevity, conventional manufacturing, connection, preparation,and other functional aspects of the system may not be described indetail. Furthermore, the connecting lines shown in the various figuresare intended to represent exemplary functional relationships and/orphysical couplings between the various elements. Many alternative oradditional functional relationship or physical connections may bepresent in the practical system, and/or may be absent in someembodiments.

It is to be understood that the configurations and/or approachesdescribed herein are exemplary in nature, and that these specificembodiments or examples are not to be considered in a limiting sense,because numerous variations are possible. The specific routines ormethods described herein may represent one or more of any number ofprocessing strategies. Thus, the various acts illustrated may beperformed in the sequence illustrated, in other sequences, or omitted insome cases.

The subject matter of the present disclosure includes all novel andnonobvious combinations and subcombinations of the various processes,systems, and configurations, and other features, functions, acts, and/orproperties disclosed herein, as well as any and all equivalents thereof.

We claim:
 1. A reaction system comprising: a susceptor configured tohold a substrate for processing; a pin embedded within the susceptor; abaseplate of a reaction region, the baseplate interacting with thesusceptor at a periphery of the susceptor; a movement element configuredto rotate the susceptor and the substrate; and a baseplate featurelocated on the baseplate; wherein a gap is formed between the susceptorand the baseplate when the pin contacts the baseplate feature; wherein asize of the gap can be adjusted based upon a location of the pin'scontact on the baseplate feature.
 2. The reaction system of claim 1,wherein the baseplate feature comprises a series of steps.
 3. Thereaction system of claim 2, wherein the series of steps have a heightranging between 0.001 and 0.05 inches.
 4. The reaction system of claim3, wherein the series of steps have a height ranging between 0.004 and0.012 inches.
 5. The reaction system of claim 1, wherein the baseplatefeature comprises a wedge.
 6. The reaction system of claim 5, whereinthe wedge has a height ranging between 0.001 and 0.05 inches.
 7. Thereaction system of claim 6, wherein the series of steps have a heightranging between 0.004 and 0.012 inches.
 8. The reaction system of claim1, wherein the baseplate feature is created by milling out of a portionfrom the baseplate, resulting in the baseplate feature comprising avertical surface, a horizontal surface, and a sloped surface.
 9. Thereaction system of claim 8, wherein the vertical surface of thebaseplate feature has a height ranging between 0.001 and 0.05 inches.10. The reaction system of claim 9, wherein the vertical surface of thebaseplate feature has a height ranging between 0.004 and 0.012 inches.11. The reaction system of claim 8, wherein a contact between the pinand the horizontal surface of the baseplate feature results inminimization of the gap between the baseplate and the susceptor.
 12. Abaseplate assembly comprising: a baseplate configured to define an areain which a reaction takes place; and a baseplate feature disposed on thebaseplate; wherein the baseplate feature is configured to interact witha pin located on a susceptor holding a substrate; and wherein a contactof the pin onto the baseplate feature creates a gap between thebaseplate and the susceptor, a size of the gap being dependent on alocation of the contact relative to the baseplate feature.
 13. Thebaseplate assembly of claim 12, wherein the baseplate feature comprisesa step.
 14. The baseplate assembly of claim 13, wherein the step has aheight ranging between 0.004 and 0.012 inches.
 15. The baseplateassembly of claim 12, wherein the baseplate feature comprises a wedge.16. The baseplate assembly of claim 15, wherein the wedge has a heightranging between 0.004 and 0.012 inches.
 17. The baseplate assembly ofclaim 12, wherein the baseplate feature is created by milling out of aportion from the baseplate, resulting in the baseplate featurecomprising a vertical surface, a horizontal surface, and a slopedsurface.
 18. The baseplate assembly of claim 17, wherein the verticalsurface of the baseplate feature has a height ranging between 0.004 and0.012 inches.
 19. The baseplate assembly of claim 17, wherein a contactbetween the pin and the horizontal surface of the baseplate featureresults in minimization of the gap between the baseplate and thesusceptor.
 20. The baseplate assembly of claim 19, wherein theminimization of the gap between the baseplate and the susceptor providesan indication of a warping status of the baseplate assembly or thesusceptor.